My son did his 16U summer with a scout team as a PO.
The scout that brought him onto the team had coached him previously, and brought him specifically to be a reliever. My son didn't have an overpowering fastball, but he had a really good sinker. He also changed speeds well. Basically he was very tough on free swinging teams. The staff was loaded with hard throwers, so my son was used once the opponents seemed to be dialed into the starter's velocity.
We live in South Florida, so we are within reasonable driving distance to many tournament locations. If he pitched more than 2 innings, he would have a day or two off and we would go home.
The team was run by a group of scouts who would bring in a handful of new players from Latin America every couple of weeks, so honestly I don't know if you could ever consider it a "team" in the typical sense. At any point half the team didn't even speak the same language as the other half.
Most of the PO's on the team were 2 way players on their school teams. Some of them were solid in the field and at bat, but projected to be pitchers as they got older. They tended to play where they had the most value for the team. In other words, every player (including the PO's) would have been above average HS fielders - but not all of the fielders were good on the mound. One of the shortstops was clocked at 90+ across the diamond, but on the mound he was just as likely to hit the batter, the backstop, or the umpire as he was to hit the strike zone. So, he didn't pitch.
I will also say that playing summer ball in Florida with 90+ temperatures tends to make a player appreciate the PO position and it's shaded comforts.